1. Chemical Equations Ms Fedor Arts and College Preparatory Academy

2. Prelab: Quickwrite 1. What toxins have you encountered in your life? 2. How can toxins enter the body? 3. How can toxins harm you?

3. Activity: Toxic Reactions Objective: interpret a chemical equation Part 1: Interpret a chemical equation Part 2: Observe different types of toxic reactions in the body

4. Prepare for the Demonstration Hydrochloric acid is corrosive. Wear safety goggles. Have extra baking soda on hand for spills. HCl(aq) + NaHCO 3 (aq)  NaCl(aq) + H 2 O(l) + CO 2 (g)

5. Discussion Notes

6. HCl(aq) + NaHCO 3 (aq)  NaCl(aq) + H 2 O(l) + CO 2 (g) ◦ The arrow is translated as “yields” or “produces” ◦ The numbers are called subscripts, they tell you what the ratio of atoms in the substance is. There is a 1:1 ratio of hydrogen atoms and chlorine atoms in hydrochloric acid There is a 1:2 ratio of carbon atoms and oxygen atoms in carbon dioxide

7. Discussion Notes (cont.) Toxins can enter the body in a limited number of ways. Toxins often react with water in the human body. Toxins may be molecular, ionic, or metallic substances.

8. Wrap Up How do chemists keep track of changes in matter? ◦ Chemical equations help chemists keep track of the substances involved in chemical changes. ◦ Chemical equations use chemical formulas to indicate the reactants and products of chemical changes. They also show what phase a compound is in. ◦ Toxins are substances that interact with living organisms and cause harm.

9. Check-in Consider this reaction between sodium cyanide and a solution of hydrochloric acid: NaCN(s)  HCl(aq)  NaCl(aq)  HCN(g) a.Write an interpretation of the chemical equation. b.Sodium cyanide is highly toxic. What is the most likely way it will enter the body?